(a) Technical Field
The present disclosure relates generally to an environmentally friendly vehicle, and more particularly, to a motor coupling device which connects a drivetrain of a hybrid vehicle to a motor, and transfers a driving torque of the motor to the drivetrain.
(b) Description of the Related Art
In general, environmentally-friendly vehicles such as a hybrid vehicle or an electric vehicle may generate a driving torque by an electric motor (hereinafter referred to as “drive motor”) for obtaining a rotating force based on electrical energy. For example, a hybrid vehicle runs in an electric vehicle (EV) mode that is a pure electric mode using only power of a drive motor or runs in a hybrid electric vehicle (HEV) mode using driving both torques of an engine and the drive motor as power. Further, an electric vehicle runs by only using a torque of the drive motor as power.
The drive motor may be connected to a drivetrain of the vehicle, e.g., a double clutch transmission (DCT). The drive motor is connected to the drivetrain through a coupling, the coupling is connected to the drive motor, and is connected to a coupling plate of the drivetrain by engagement of a gear form so that a driving torque of the drive motor may be transferred to the drivetrain.
However, in conventional systems, when rotation angular acceleration of the driver motor is changed (e.g., upon regenerative braking) while a driving torque of the drive motor is transferred to the drivetrain through a coupling, a nonlinear behavior may be generated due to an inertia difference between the drive motor and the drivetrain. When a direction of the driving torque is changed, impact or excessive noise or vibration may be generated.
In order to solve these problems, conventional systems apply control by reducing a torque change rate around backlash generation or applying an additional damping element. However, such systems rely on backlash through a proper mechanical design of an element to fundamentally connect the drive motor to the drivetrain such as through a coupling.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the related art that is already known in this country to a person of ordinary skill in the art.